Return promise in node.js-CodePudding

i try to return data in node.js from a APIs , but I'm having problems, because I need an asynchronous function, I couldn't understand for sure the correct use of the promise, I've tried everything and I couldn't put the result in the return, only in the console.log, somebody help me?

const express = require('express')
const MFA = require('mangadex-full-api')

module.exports = {
    async indexManga(req, res) {
         
        const mangalist = MFA.login('DarksGol', 'R@ul1605', './md_cache/').then(async () => {

            manga = []
                await MFA.Manga.search('Kiss').then(results => {
                results.forEach((elem, i) => {   
                    let obj = {}
                    obj.status = elem.status
                    obj.title = elem.title
                    
                    manga.push(obj)
                })
            }).catch(console.error)

            return manga

        }).catch(console.error) 

        console.log(await mangalist)
        return mangalist
    }
}

no error occurred, only infinite loading on request

const express = require('express')
const routes = express.Router()

const searchManga = require('../src/controllers/searchManga')

routes.get('/searchManga', searchManga.indexManga)

module.exports = routes

CodePudding user response：

I don't see why this would cause "infinite loading on request", but you could greatly simplify the code to just

const express = require('express');
const MFA = require('mangadex-full-api');

module.exports = {
    async indexManga(req, res) {
        await MFA.login('DarksGol', 'R@ul1605', './md_cache/')
        const mangaList = [];
        const results = await MFA.Manga.search('Kiss');
        results.forEach(elem => {   
            mangaList.push({
                status: elem.status,
                title: elem.title,
            });
        });
        return mangalist;
    },
};

CodePudding user response：

Looks like indexManga is an endpoint. Each endpoint function must end the request-response cycle by sending a response ( res.send(), res.json(), res.end(), etc). If indexManga s an endpoint, the solution would be:

...

//return mangalist
res.send(mangalist)

//return mangalist
res.json({ status: "success", message: "logged in successfully" })

If it is a meddleware:

async indexManga(req, res, next) {
  ...
  //return mangalist
  return next()
}

EDIT: you are using async/await with .then() improperly in some places. Try this way:

module.exports = {
    indexManga(req, res) {
        MFA.login('DarksGol', 'R@ul1605', './md_cache/').then(() => {

            manga = []
            MFA.Manga.search('Kiss').then(results => {
                results.forEach((elem, i) => {   
                    let obj = {}
                    obj.status = elem.status
                    obj.title = elem.title
                    
                    manga.push(obj)
                })
                
                res.json({ status: "success", data: manga })
                
            }).catch((err) => {
               res.json({ status: "fail", error: err })
            })
            

        }).catch((err) => {
           res.json({ status: "fail", error: err })
        })
    }
}